Elastic Properties of the Respiratory System in Infants with Cystic Fibrosis

• Published in: American journal of respiratory and critical care medicine Vol. 170; no. 5; pp. 505 - 507
• Main Authors: Tepper, Robert S, Weist, Andrea, Williams-Nkomo, Tamica, Kisling, Jeffrey
• Format: Journal Article
• Language: English
• Published: New York, NY Am Thoracic Soc 01-09-2004; American Lung Association; American Thoracic Society
• Subjects: Airway management; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Case-Control Studies; Compliance; Cystic fibrosis; Cystic Fibrosis - physiopathology; Elasticity; Female; Functional Residual Capacity; Humans; Infant; Intensive care medicine; Lung - physiopathology; Lung Compliance; Male; Maximal Expiratory Flow-Volume Curves; Medical sciences; Regression analysis; Respiratory system; Vital Capacity; Human; Mechanical compliance; Intensive care; Respiratory disease; Metabolic diseases; Cystic fibrosis; Infant; Respiratory system; Genetic disease; compliance; Digestive diseases; Elastic properties; pressure-volume curves; Resuscitation; Pancreatic disease
• ISSN: 1073-449X; 1535-4970
• DOI: 10.1164/rccm.200401-132OC

Respiratory system compliance (Crs) in infants with cystic fibrosis (CF) has been reported as decreased or not different compared with healthy control subjects; however, the reported measurements of Crs were "quasi-static" or by the single-breath occlusion technique, with all measurements limited to tidal lung volume, as well as using inspiratory rather than expiratory pressures. We compared the passive elastic properties of the respiratory system of sleeping infants with CF (n = 10) and healthy control subjects (n = 34) by measuring static deflation pressure--volume (PV) curves from a lung volume at 30 cm H(2)O (V(30)) to FRC. There was no significant difference between the groups for Crs, which was measured as the slope between airway relaxation pressures of 5 and 15 cm H(2)O, the linear portion of the deflation PV curve. In addition, when PV curves were normalized to V(30), there were no differences between the infants with CF and healthy control subjects in the fractional volumes at any airway pressure. The infants with CF had significantly lower forced expiratory flows; however, lower flows did not correlate with fractional volumes measured from the PV curve. Our findings indicate that infants with CF have normal elastic properties of the respiratory system.